The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. In the course of integrated circuit evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component or line that can be created using a fabrication process) has decreased.
Semiconductor memory devices are also continually shrinking in size while at the same time increasing in density or volume and operating at a lower power. The operations of memory devices are synchronized with various control signals and data signals. As the signal paths for signals shrink in size, the resistance of the signal paths increases. An increase in signal path resistance results in various problems, such as causing a speed bottleneck in the memory.